The present invention relates to swivel joints for interconnecting two fluid conduits in a manner that allows rotary motion therebetween; and more particularly to such joints which are used to connect components of pneumatically powered surgical tools.
The use of pneumatically powered surgical and dental tools has become established and wide spread because of the high rotational speeds which can be achieved by air motors of relatively small size in comparison to electric motors. The tool is connected to a source of compressed air by two conduits, either a pair of hoses or a single hose with two conduits therein. One of the conduits supplies compressed air to the surgical tool. The other conduit carries the exhaust air from the tool back to the source of compressed air because it is disadvantageous to vent the exhaust air at the tool which could adversely affect the surgical site. U.S. Pat. Nos. 4,260,382; 4,431,412 and 4,521,189 describe dental tools of this general type.
However, the use of power-driven surgical tools has been hindered somewhat by the lack of flexibility and movement of the hand piece of the device gripped by the surgeon. The surgeon must be able to manipulate the tool into a variety of positions while operating on a patient and the hose supplying pressurized air to the tool often restricts that movement. Therefore, it is desirable to couple the air hose to the surgical tool in a manner which allows free rotation to occur between those two components. However, the coupling between the components must be air tight and air from the inlet conduit cannot leak to the atmosphere or to the outlet conduit.